


the laws of physics

by peterstank



Series: we didn’t know we were making memories, we were just having fun [1]
Category: Marvel Cinematic Universe
Genre: Endgame compliant, F/M, Infinity War Compliant, Mentions of other characters - Freeform, endgame spoilers, peter and morgan interact or we riot, this was inspired by that really sad song from up
Language: English
Status: Completed
Published: 2019-05-20
Updated: 2019-05-20
Packaged: 2020-03-07 17:43:54
Rating: Teen And Up Audiences
Warnings: Major Character Death
Chapters: 1
Words: 3,676
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/18878074
Author URL: https://archiveofourown.org/users/peterstank/pseuds/peterstank
Summary: “I wish he’d come back.”Peter isn’t sure what to do with himself. His heart breaks into a million pieces as those words spill out of her mouth. He wants to fall down and cry, but he can’t. Morgan needs him to be strong, so Peter nods while his eyes prickle. “Yeah, me too. But I don’t think...”“Youcame back.”“Morgan...” he reaches for her and then stops himself. She doesn’t know him, he’s just another black-clad stranger in her house. “I’m sorry,” is all he can think to say.Morgan tilts her head. “Daddy figured out time travel for you. He told me before he left, said everything was gonna be okay. He was gonna get Petey back and I could meet my big brother—”{post endgame: morgan & peter meet}





	the laws of physics

There is a bright spot in the back of his mind, a warmth that lingers even after all of these years. He can remember the feeling of the sun, hot against his skin, and the sound of laughter. The rest is hazy, a strange amalgamation of good moments that just won’t leave. They stick with him the way he sticks to walls, clinging to the recesses of his subconscious.

Fingers, wet with paint, stained red, dragging across his cheeks. His father: brown eyes, full of a light that went out one day, a hope that didn’t last. Bubbles floating through the air only to be swallowed with a pop. 

That’s all he can really remember of his parents until their funeral.

The details had been fading but Peter can recall them easily now. His suit had been too big and too scratchy, his tie had been choking him, just like now. He had been tired and walking around in a daze, one hand hanging limply from Ben’s grip. He hadn’t cried that day, because he’d wanted to be strong. May had been crying so much and even Ben, and someone had to be strong, right? 

But he’d cried that night. Curled up against cold white sheets, so different from his patterned ones back home. Had they been Winnie the Pooh printed or Toy Story? He can’t remember.

His pillow had been soaked and no one had come to check on him. The tears had been silent, smothered by the storm outside his window.

You didn’t have to be strong when you were alone.

With Ben, he’d forgotten that. With Ben the storm had soaked through his sweatshirt, right down into the hollows of his bones. They’d been standing in the cold, in an alley, and then the next Peter knew his hands were pressing against a gaping hot wound, fingers stained red with blood, the sobs folding his body in half as he begged and begged and begged.

_Please, don’t go, I don’t want you to go, I don’t want you to die Ben..._

That funeral had been a quiet one. May had held his hand, and his grip had been firmer for her. He wanted her to know she had something solid to fall back on. He’d watched her out of the corner of his eye, keeping track of the way her chin wobbled, of how she stumbled every so often, the weight of the world stacked up against her.

He hadn’t been able to save Ben, but he wanted to save her in any way he could.

Things went from before the bite and after. Before was Ben, his parents, and all the sadness. After was something else. After came the realisation that life could only be good if you made it that way.

He wanted to help people and with his powers, he could. Soon his days were a flurry of activity. He was too busy to think much about what he’d lost, focusing only on what he’d gained. Super strength, enhanced senses—it was surreal, but more believable than the idea that the bad things would ever triumph. In Peter’s world, at least then, heroes still saved the day in the end.

Now it’s the end of the day and the hero hasn’t come home. He won’t ever.

Peter’s hands curl around the porch railing. His knuckles are white, his breathing is rushed, his throat is searing. He’s too deep in to concern himself with the possibility of splintering the wood or even ripping this whole house apart with his bare hands because it burns so much inside of him, _nothing is right._

He’d been standing there, staring while Peter rambled like an idiot. Peter had been too hurried to notice the little things, like how grey his hair had gotten and the tears forming in his eyes. But then it didn’t matter because Tony’s arms were around him, and even with the suits they wore it was warm, the first semblance of the good parts of his Before that he’d had in years.

Tony had kissed his cheek and if they hadn’t been about to die, Peter’s pretty sure he would have made some quip about how he was only greeting him in a proper Italian fashion; it hadn’t meant anything, not really...

“Hi.”

Peter jumps, startled right out of the attack he hadn’t realised he was on the verge of. All at once the breath is stolen from his lungs. He whips around, hastily wiping at his cheeks.

Morgan Stark stares up at him with all of that unnatural intelligence and scrutiny. She reminds him of MJ, which is a weird thing to say about a four year old kid. She’s clutching a stuffed bear in her arms, only it’s fur is red and gold. It’s an _Iron Man_ bear.

“W-What?”

“I said hi,” she repeats, taking a step closer. Her eyes don’t leave his face. They’re grey and blue, they’re Tony’s eyes. This is Tony’s kid, a living reminder that what had been a blink for Peter had been five years for everyone else. “You’re supposed to say it back.”

“Hi,” Peter says.

Morgan Stark brightens. He’s stupidly envious of the naivety that comes along with being a kid. Peter wishes he could be that small again, so small you weren’t sure what was happening or why everyone was so upset, stubbornly yanking at the buttons choking your throat.

“You’re Peter,” she tells him. “Daddy told me lots about you. Said you were the best Avenger of all time, and that he missed you tons and tons.”

Peter stares. There are a thousand things he wants to say, but none of them belong in this conversation. She’s just a kid, she shouldn’t have to deal with his stupid insecurities. 

One look at her and he knows, he understands. Why May took him in, not just for Ben but because she loved him. Peter was never a big believer in all that stupid love at first sight stuff but with Morgan, it sort of makes sense. He’s pretty sure he’d do just about anything for her if she asked, or even if she didn’t. She’s all that’s left of Tony, the last real piece of him that’s left in the universe,

(and she takes his stunned silence in stride, tugging the ear of her teddy between her lips to chew on, blinking innocently up at him)

but he can already tell she’s her own thing, too.

Peter clears his throat, trying to salvage the last dregs of his clarity, and kneels down in front of her. “I um... I miss him, too.”

“Tons and tons?”

“Yeah,” he says. “Definitely.”

“A ton is two-thousand pounds.”

Peter blinks. “Uh, yeah. That’s right, it is.”

“So you miss him three-thousand,” she proclaims, and then nods to herself like it makes all the sense in the world. “I wish he’d come back.”

Peter isn’t sure what to do with himself. His heart breaks into a million pieces as those words spill out of her mouth. He wants to fall down and cry, but he can’t. Morgan needs him to be strong, so Peter nods while his eyes prickle. “Yeah, me too. But I don’t think...”

“ _You_ came back.”

“Morgan...” he reaches for her and then stops himself. She doesn’t know him, he’s just another black-clad stranger in her house. “I’m sorry,” is all he can think to say.

Morgan tilts her head. “Daddy figured out time travel for you. He told me before he left, said everything was gonna be okay. He was gonna get Petey back and I could meet my big brother—”

It’s too much for him, it hurts too much. The tears spill over and a sob escapes him before he can stop it, and Morgan halts her rambling to oogle at him. Then she reaches out and with all the gentleness of Pepper, all the kindness of Tony, her hands cup his cheeks. The bear falls onto the ground between them.

“It’s okay,” she says. “We’ll figure it out someday too. When we’re big and strong.”

Peter nods, even if he knows they won’t. There’s nothing that can bring Tony back—

( _you can’t actually time travel_ , he’d told Ned once. _That’s like, totally against the second law of thermodynamics._ )

But then, Captain America’s shield doesn’t follow the laws of physics, and Einstein had never left planet earth, so what the fuck does he know about relativity anyway?

He’s so deep inside his own brain he hadn’t processed when Morgan had wriggled up against him and manually wrapped his arms around her. She settles against his shoulder with a sigh.

It’s then that he finally catches up with what she’d said. Tony had told her that Peter was her brother, her big brother, and he was going back in time to _save him._

Morgan shivers. “Are you cold?” Peter asks, and with her small nod he leans back a little to work off his coat. They put it on her, and the heavy scratchy material is enough to shield her from the light breeze around them.

Peter swipes a loose strand of hair behind her ear. “Tired?”

She shrugs. “I don’t know anybody, ’cept you and mommy and May.”

“You know May?”

Morgan nods sleepily, not understanding how mind blowing that is for him. He and May have hardly had a chance to really talk about anything. He had hugged her after it was all over, cried with her some, and then Happy was there to fill the silences and drive them upstate to this tucked-away cabin in the woods that houses even more technology than the lab at the Avengers Compound.

“She came by sometimes to see mommy,” Morgan says sleepily. “They’d drink the Purple Adult Juice and cry and laugh and act all weird. Sometimes mommy and me would visit her in the city and bring her food cuz she was super duper lonely.” Morgan wrinkles her nose. “I guess you guys will be bringing us the food now, huh?”

Peter’s mouth falls open. Then he smiles. “Yeah, probably. What’s your favourite food, anyway?”

“Cheeseburgers!” She says, bouncing a little.

“No kidding! That’s my favorite food, too!”

She grins. “Happy said he would get me all the cheeseburgers I want,” she tells him. “Daddy liked cheeseburgers too.”

“Everyone likes cheeseburgers,” Peter says. “That’s one of the laws of physics.”

“Nuh-huh!”

“Yeah so!”

“Liar, that’s not one of them!”

She’s still grinning and he is too, the smile is so painful but there’s something light blossoming in his chest that makes it all worth it. “You think you know all the laws, then? Go on, show me.”

Morgan rolls her eyes. “Newton’s Laws of Physics are threefold,” she begins, with all the lazy authority of Tony Stark. “Number one: in- _inertia_. A body will remain at rest or moving at a constant velocity unless it is acted on by an unbalanced force—”

“Do you even know what any of that means?”

“I do so,” Morgan says. Then she shoves him. “ _Inertia_.”

Peter can’t help smiling. “Alright, what about Ohm’s Law?”

“I’m not finished with Newton!”

“Okay, okay,” Peter holds up his hands placatingly. “Go on, Dr. Stark.”

This only seems to please her. She puffs up. “Numbe two: F=ma. Force equals mass times esseler—excel— _acceleration_.” Then she deflates. “I don’t know what that one means.”

Peter isn’t surprised. She’s only four after all, even if she is Tony Stark’s kid. “It’s like, how you’d work out how much force you’d need to push a car that’s out of gas. It’s a formula.”

Morgan absorbs that and nods. “Oh.”

“What else, little miss?”

“Number three!” Morgan says loudly, “for every action there is an equal and opposite reaction... like... uhhh....”

“Like a bird, maybe?” Peter suggests, so as not to put her down. “It flaps its wings and the air is pushed downwards, but the air is pushing it up at the same time. Action versus reaction.”

“That’s correct,” Morgan says with a satisfied nod. “But there’s no law about cheeseburgers, Petey.”

“There is so.”

“Prove it!”

“E=MC2,” Peter says, and she starts to protest. “Mass can be converted into energy, therefore the more mass I have in my body the more energy I have. Therefore I have to eat cheeseburgers.”

Morgan shakes her head. “That’s stupid.”

“I’ll admit it’s pushing it a little,” Peter relents.

Morgan giggles. “Everybody Must have Cheeseburgers,” she says. “Squared.”

Peter grins again. “See, you’ve totally got it. You should join my decathlon team, you’d give MJ a run for her money.”

“Who’s MJ?”

“A friend,” Peter says, and his pulse jumps at the thought of MJ surviving the snap, ageing five years, going to college while he floated around in Titan’s atmosphere as particles of dust.

“Your cheeks are all red,” Morgan tells him, poking each one with a finger. “Do you _loooove_ her?”

“No,” Peter says, because he so doesn’t. It just isn’t possible. She’s MJ. Morgan is grinning at him though and Peter rolls his eyes. He wastes no time picking her up so at least he doesn’t have to look at her while he has a crisis. “I don’t. Really.”

“Liar,” she says. “You’re like a tomato.”

“Last I checked tomatoes weren’t known for lying.”

“No,” she argues, all frustrated. “You’re—you’re _dumb_ , Petey.”

The laugh bursts out of him, startles him. All he can think is, she’s Tony’s kid through and through. “I hope I haven’t disappointed you.”

“Nah, Daddy said you were stupid. Always getting yourself into trouble and stuff, and then he’d go and save your stupid sorry butt.”

 _There’s no one to save me now_ , he thinks, but holds Morgan a little tighter as he walks them back inside because it isn’t about him anymore. Just like that, it’s about her, saving her, keeping her safe.

“I may be stupid,” Peter says, “but I’m not sorry for it.”

Morgan snorts, a huff against the crook of his neck where her nose is pressed, one arm around his neck and the other clutching her Iron Bear. Inside, it’s dim and clearing out. Only a few remain: Pepper and May, Happy, and Rhodes. 

Pepper’s eyes widen when she sees them. “Peter—oh, god, I’m so sorry—”

“No, it’s okay.” Peter instinctively clutching Morgan a little tighter. “It’s fine, Mrs. Stark, really.”

“I’m tired,” Morgan reminds him, even more so now that she can partially rest against him. Her words are a sleepy mumble and he’s pretty sure he’s the only one who heard.

“Where’s her room?”

Pepper blinks. “U-upstairs,” she stammers. “In the back. Her name is on the door, you can’t miss it.”

“Unless you can’t read,” Morgan quips softly. “Bet you’re so stupid you can’t.”

Peter hides his amusement, nodding and ascending the steps. He pretends he can’t hear them whispering as soon as he leaves, forgetting about his heightened senses. Happy mutters something about how it’s good Morgan has him, and Pepper starts to cry a little. He tunes them out after that.

Morgan’s room isn’t hard to miss at all, a small cozy place with a sloping roof and white wood walls. Peter peels the covers back with one hand and smiles to himself. He lays her down against the Spiderman sheets.

“You good?”

She’s clutching his wrist. “No,” she whispers.

Peter’s hand halts at the bedside lamp. Instead of turning it off, he kneels down to face her. “Do you wanna cry?”

Morgan shakes her head, glum, it’s all hitting her at once now that there’s no one to hide behind, no sun to ward away the monsters. “I just want daddy.”

Peter nods. He might cry, already is, sort of. He swallows the lump in his throat and squeezes her tiny hand. “What would Daddy do if he was here?”

Morgan wipes her eyes before her tears can fall. She’s stubborn already. “He’d tell me a story.”

“Yeah?” Stories he can do. “What kind?”

“Once upon a time Morguna went to bed, the end.”

Peter shakes his head with. “That’s the worst story I’ve ever heard.”

“I know! It’s not even a story.” Morgan sits up and flops back down again in one go, eyeing him with exasperation. “When did you meet daddy? He never said.”

Suddenly the smell of smoke and the sound of screaming fills his senses. It’s like he’s back there, rubble all around him, the metallic clang of a hero-less suit moving, advancing. “I was eight—”

“Eight?! Daddy said you were fourteen!”

“I thought you said he never told you how we met?”

Morgan sinks back against her pillows sheepishly. “I lied.”

Peter pokes her. “Guess that makes you a tomato, too, huh?”

“No,” Morgan protests, pouting a little as she burrows under her blanket. “I’m an onion.”

“How do you figure that?”

“Onions have layers,” she says, with the worst fake accent he’s ever heard. “Plus they’re not red.”

Peter pinches her nose without even thinking about it. “Onions also stink and make you cry, and some of them are red, too.”

Morgan rolls her eyes. “Red onions are really purple.”

“ _You’re_ purple.”

“You’re pink!”

He gives an offended gasp and Morgan swells with victory. She pats his head. “You can go on.”

“Oh, can I? Well that’s good to know, Your Highness, I was getting worried there for a second—”

“Peter!”

She reaches out to push his shoulder with a little hand and Peter pretends to fall down dramatically. His eyes roll back into his head and he clutches at his heart, twitching around on the floor. Morgan squeals and tears out of bed, clambering on him. “Petey! Stop!”

She pokes him in the gut and he grunts out a laugh. “Alright, alright, back into bed, Shrek.”

Morgan wrinkles her nose. She takes off her buckled black shoes, something he’d forgotten to do the first time around, and wriggles her toes beneath her lace-collared socks. “Hulk is Shrek, isn’t he?”

She whispers, like it’s the world’s biggest secret.

“ _Bed_.”

“Story,” she counters.

Peter relents, but insists on getting a blanket on her at least. He jokingly throws it over her head and she rips it off, her hair going static, and Peter ruffles it up more just to mess with her. “Why does it do that?”

“Your hair?” Morgan nods. “It’s an imbalance of electric charges. Like, the blanket has a charge and so do you, and the electrons are leaping between you. Your charges oppose each other.”

Morgan reaches up, rubs her hair, and grins when sticks to her palm to stand straight up. “It’s like the playground slides.”

Peter remembers that, being six years old in a fleece sweater, zapping everything and everyone he touched and feeling sorry when they gasped in discomfort. He figures Morgan would just cackle and run away, or zap him again.

“Tell me?”

Peter blinks. Story, right. “So I was eight, and it was nighttime. We were leaving this event—the whole backstory is complicated, but whatever. It was me, May, and my Uncle Ben, and a bunch of evil robots.” Her eyes widen. “They were going haywire and totally attacking everyone, and I managed to get separated from May and Ben. I was all alone, and totally freaking out, and I was wearing one of those cheap plastic Iron Man masks they sell at the costume stores—”

“I have one of those,” Morgan says, “’cept it’s not fake and it’s not mine.”

Peter grins through her outburst. “I was totally obsessed with your dad. Like, posters on my wall, t-shirts, Iron Man bedspread, the whole shebang.”

Morgan glances down at her bedsheets and blushes. “Don’t think about it,” she tells him warningly, in a tone perfectly reminiscent of Pepper.

Peter pretends not to. “So I was standing there in this screaming crowd, and everyone was running from the robots, but I didn’t feel like running.”

“I thought you were scared?”

“I was, but just because you’re scared doesn’t mean you can’t be brave. I just knew I wanted to stop the bad guys.”

“So did you turn into a spider and eat them?”

“What?” Peter laughs. “No, no that’s not how that works. And I didn’t really do anything. I just held my hand out toward one, like I’d seen your dad do, and the next thing I know Mr. Stark is right next to me blasting the thing to pieces.”

Her eyes widen. “Daddy killed an evil robot?”

“Oh yeah,” Peter nods. “It was like, the most awesome thing that had ever happened to me in my whole life.”

Morgan smiles, and then hesitates. “Daddy didn’t know it was you he saved, did he?”

“No,” Peter confirms. “He didn’t. I wish...”

_I wish I could tell him._

“So is that when you decided you wanted to be Spiderman?”

Peter halts. His words die in his throat. All he can taste is iron. “No. That um... that part came later.”

She stares at him for a long moment. “Is it a sad story?”

Peter nods. “Yeah, pretty much.”

“I’m sorry,” she whispers. 

“That’s okay.” Peter tries for a smile. “I’ll tell you some other time, okay?” _When it doesn’t hurt so much, when it doesn’t make me feel like screaming._

Morgan nods. “Okay.”

She falls back against her pillow and closes her eyes, before opening them again. “I’m glad you came back, Petey.”

Peter can’t stand it. His eyes burn and the tears fall over against his will. He leans forward and presses a kiss to her forehead, like May does for him when he’s sick or sad or lonely. “Me too, squirt.”

“That’s Professor Doctor Onion Squirt to you, Mr. Spiderman.”

Just like that she manages to wrangle one last laugh out of him. Peter smoothes her hair down and stands. She’s already curled up by the time he turns the lights off. Peter makes sure to keep the door cracked, just in case she starts to cry. Pepper will hear her better that way.

**Author's Note:**

> Woooosh so it’s been a really long time since I’ve written anything set in a modern era, I seriously hope it wasn’t absolute shit. I just can’t get Peter & Morgan out of my head, and I’ve been reading all the fics they’re featured in just to get my fix. 
> 
> Please tell me your thoughts! I have plans to continue :) 
> 
> (Also in my head that cheek kiss is CANON I don’t care if they scrapped it, it happened, we all saw it)


End file.
